| Abstract: | Abstract A sensitive and specific fluorimetric assay for 6-mercaptopurine (6-MP) is described. The method consists of enzymatic (xanthine oxidase) conversion of 6- MP to the oxypurine derivatives, followed by oxidation with acidic chromate to the corresponding 6-sulfonate. The fluorescent product has excitation and emission maxima at 330 and 400 nm, respectively. The good recovery and reproducibility were obtained. The sensitivity (the smallest amount detectables) was about 22 pg/ml for 6- MP in water. Different spiked serum samples containing 6-MP and azathioprine (AZA) were also analyzed and the sensitivity for 6-MP was about 2.2 ng/ml. |
